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B.Sc. (IT) - MICROPROCESSOR SYSTEM

Time : 03 Hours Maximum

Marks : 75

Instruction to Candidates:

1) Section - A is compulsory.

2) Attempt any Nine questions from Section - B.

Section - A - (Q1) (15 x 2 = 30)

a) What is the function of assembler?

b) Explain the difference between machine language and theassembly language in INTEL 8085 microprocessor.

c) How does a microprocessor differentiate among a positive

number, a negative number and a bit pattern?

d) If the memory chip size is 1024 x 4 bits, how many chips

are required to make up 2048 bytes of memory?

e) Why is the direction of data flow in address bus?

f) In a peripheral mapped I/O, can an input port and output

port have the same port address? Justify your answer.

g) What is machine cycle?

h) What is opcode?

i) Why are program counter and stack pointer in INTEL 8085

microprocessor 16 bit register?

j) Is there a minimum pulse width required for the interrupt

signal?

k) Write instruction to :

(a) Load 08H in the accumulator.

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(b) Increment the accumulator.

(c) Display the answer.

l) If the INTEL 8085 microprocessor adds 89H and 79H

specify the contents of accumulator and status of S, Z and

CY flags.

m) The following instructions subtract two unsigned numbers

in INTEL 8085 microprocessor. Specify the contents of

register A and status of S and

CY flags. Explain the significance of the sign flag if it is set.

MVI A, F8HSUI 69H

n) Explain how many times the following loop will be

executed in INTEL

8085 microprocessor :

LXI B, 0007H

LOOP:DCX B

JNZ LOOP

o) Write the instruction to load the number 2050H in the

register pair BC in

INTEL 8085. Increment the number using the instruction INX

B and

illustrate whether the INX B instruction is equivalent to the

instructions

INR B and INR C.

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Section - B - (9 x 5 = 45)

Q2) Draw the functional block diagram of INTEL 8085

microprocessor.

Q3) How address decoding is done in INTEL 8085

microprocessor?

Q4) Explain the operations commonly performed by MPU.

Q5) Describe the functions of different flags of ALU of INTEL

8085 microprocessor.

Q6) Explain why demultiplexing is done for bus AD7 - AD0 in

INTEL 8085 microprocessor.Q7) Describe TRAP, RST 7.5 RST 6.5 and RST 5.5 interrupts

in INTEL 8085 microprocessor.

Q8) Explain the functions of ALE and IO / M signals in

microprocessor.

Q9) Give the block diagram for memory chip 8155.

Q10) Specify the register contents and flag status (S, Z CY)

after the instruction

ORA A is executed in INTEL 8085 microprocessor.

MVI A, B9H

MVI B, 47H

ADD B

ORA A

Q11) Sixteen bytes of data are stored in memory locations

at XX50H to XX5FH in INTEL 8085 microprocessor. Write a

program to transfer the entire block of data to new memory

locations starting from XX70H. The data in hexadecimal code

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are : 37, A2, F2, 82, 57, 5A, 7F, DA, E5, 8C, A7, C2, B4, 10,

19, 98.

Q12) Write a program to add the following data bytes stored

in memory locations starting at XX60H in INTEL 8085

microprocessor and display the sum at the output port if the

sum does not generate a carry. If a result generates a carry,

stop the addition, and display 01H at the output port. The

data in hexadecimal code is

First set : 37, A3, 24, 78, 97.

Second set : 12, 1B, 29, 42, 07.Q13) Write a main program in INTEL 8085 microprocessor to

count continuously in binary with a one second delay

between each count. Write a service routine at XX70H to

flash FFH five times when the program is interrupted, with

some appropriate delay between each flash.